The present invention relates to automotive vehicles. More specifically, the present invention relates to a system for controlling the charging of a vehicle battery.
Automotive vehicles powered by combustion engines typically include a rechargeable battery. The battery is used to provide cranking power to start the vehicle and also is the only source of power to continue to maintain the lights or other devices in operation when the vehicle ignition has been turned off. When the vehicle is running, the engine is used to charge the battery. Additionally, the engine is also used to power electrical components of the vehicle when the engine is running.
Vehicles contain charging systems, simply referred to as an xe2x80x9calternator,xe2x80x9d which are powered by the engine and used to charge the battery. Typical charging systems include a simple voltage regulator connected to the output of an alternator. The voltage regulator is used to set a voltage generated by the alternator which is applied to the battery.
In the automotive industry, the drive towards greater fuel efficiency and lower exhaust-gas emissions has led to the development of xe2x80x9cstart-stopxe2x80x9d vehicles in which the vehicle engine shuts off at stop lights, traffic jams, etc., and restarts automatically when the driver steps on the accelerator pedal. Frequent shutting off of the engine in such vehicles prevents the alternator from charging the battery evenly. Thus, the battery charge can deplete relatively fast in such start-stop vehicles. Further, a typical alternator is not designed to fully restore a depleted battery, but rather to maintain a healthy one. Thus, it is possible for a start-stop vehicle, that employs a prior art charging system, to automatically shut off at a stop light or traffic jam and not be able to start again until the depleted vehicle battery is boosted from a booster battery or the vehicle is jump started by another vehicle.
A system for controlling charging of a battery of a vehicle powered by an internal combustion engine is provided. The system includes an input that receives an engine shutdown signal indicative that the engine will be shut down during an idle period to thereby conserve fuel. An engine shutdown delay delays shutdown of the engine for a shutdown delay period in response to the engine shutdown signal. Charge boost circuitry increases a charge signal applied to the battery of the vehicle during the engine shutdown delay period.